London has been battered by 50mph winds that have felled trees and caused travel chaos. Powerful gusts swept across the capital as the Met Office issued a yellow "be aware" weather alert for most of the country.

Trenton Oldfield, who disrupted this year's Boat Race by swimming into the path of the crews on the Thames, was today sentenced to six months in jail at Isleworth Crown Court after he was convicted of causing a public nuisance.

Oldfield, supported in court by a throng of well-wishers, smirked as Judge Anne Molyneux passed sentence.

But he looked surprised as the jail term was handed down.

The judge said Oldfield had acted dangerously, disproportionately, had not shown what he was actually protesting against, and displayed prejudice in sabotaging the event which Oldfield regarded as elitist.

Judge Molyneux said Oldfield ruined the race for everyone.

"You caused delay and disruption to it and to the members of the public who had gone to watch it and to enjoy the spectacle of top athletes competing," she said.

"The rowers had trained for many months.

"You had no regard for the sacrifices they had made or for their rigorous training when you swam into their paths."

Adding that Oldfield's actions had endangered his life and those of others, the judge said: "You decided that you had the right to stop members of the public enjoying a sporting competition which they had chosen to go and watch.

"You did not have that right.

"You did nothing to address inequality by giving yourself the right to spoil the enjoyment of others.

"In doing so, you acted without regard for equality and contrary to the meaning of it.

"You made your decision to sabotage the race based on the membership or perceived membership of its participants of a group to which you took exception.

"That is prejudice.

"Every individual and group of society is entitled to respect.

"It is a necessary part of a liberal and tolerant society that no one should be targeted because of a characteristic with which another takes issue.

"Prejudice in any form is wrong.

"Your offence was planned. It was deliberate. It was disproportionate. It was dangerous.

"You have shown no regret."

Oldfield would not be deterred from protesting again, his wife, Deepa Naik, said.

Speaking outside court, the 35-year-old attacked Britain and London as being brutal and deeply divided.

She said: "Trenton has spent his adult life working on these issues and his direct action protest on the 7th April 2012 was a natural extension of his everyday work.

"Trenton's protest was a reaction to an increasingly brutal business, media and political elite."

She added: "Great Britain has convinced many it is the home of democracy and the gauge of civilisation. Anyone living here today knows Britain is a brutal, deeply divided, class-driven place.

"London today is the most unequal society in the Western world . This poverty and inequality is entirely unnecessary and has been severely exacerbated by Government cuts and reductions in civil liberties."

He was found guilty at London's Isleworth Crown Court last month of causing a public nuisance and is due to be sentenced at the same court.

The annual contest, won by Cambridge, was described as one of the most dramatic in its history after the wetsuit-clad swimmer was spotted in the vessels' path.

The drama continued after the interruption when the blade of an Oxford oar broke and the crew's bowman Alex Woods collapsed at the end and was taken to hospital.

Oxford president Karl Hudspith wrote on Twitter: "To Trenton Oldfiled (sic); my team went through seven months of hell, this was the culmination of our careers and you took it from us."

William Zeng, who was also in the Oxford boat, described Oldfield as "a mockery of a man" who had protested against the right of the crews to devote "years of their lives, their friendships and their souls to the fair pursuit of the joys and the hardships of sport".

Judge Anne Molyneux said last month that all options were open, including jail.

During the trial Oldfield told the jury the race was a symbol of elitism in Government and that London "has the highest inequality in the western world".

He said: "(The boat race is) a symbol of a lot of issues in Britain around class, 70% of Government pushing through very significant cuts are Oxford or Cambridge graduates.

"It was a symbolic gesture to these kind of issues."

Oldfield, an Australian who moved to the UK in 2001, decided to make the protest after learning of Government plans to "sell off" the NHS and "snoop" on electronic communications, and after hearing encouragement given to "dob in" people planning protests during the Olympics.

He said some spectators believed his actions had improved the race. "Lots of people thought it made it the most exciting Boat Race ever," he said.

Prosecutor Louis Mably told jurors the contest was spoiled for spectators watching from the banks of the River Thames or live on BBC TV, not to mention the two teams.

Oldfield, of Myrdle Street, east London, worked and volunteered for a decade in jobs and projects aimed at increasing better prospects for people in impoverished areas.